Knifes and drills, manipulator probes, spring coils, probe microscope styli, and coils used with finely detailed electronic circuitry used in processing of microscopy samples are required in a wide range of fields, and great expectations are placed upon such manufacturing technology with regards to manufacturing ultra-fine three-dimensional structures. In the conventional manufacture of these types of ultra-fine three-dimensional structures, trials have been made whereby blocks of material etc. are formed using mechanical processing and are then cut using sputter-etching techniques. This method is relatively straightforward if the subject of manufacture is linear in shape such as is the case with a manipulator probe or probe microscope stylus, but is extremely complex in the case of a three-dimensional shaped item such as a drill or coil, etc.
Further, in addition to the aforementioned sputter-etching techniques and also in addition to other methods for removing material such as gas assisted etching and chemical etching techniques, processes of adhesion to materials referred to as CVD (Chemical Vapor Deposition) techniques are also used as fine processing technology for semiconductor devices and masks etc. used in the manufacture of such semiconductor devices. Technology for forming ultra-fine three-dimensional structures using CVD techniques is also being developed amongst researchers. There are methods employing laser beams, focused electron beams and focused ion beams as the beams for use in the CVD techniques. With deposition using CVD techniques, the dimensions of accumulated portions depend on the beam diameter and it is therefore necessary for beam diameter to be narrow in the manufacture of these kinds of ultra-fine three-dimensional structures. When laser light is used, there are limitations due to the beam diameter and wavelength coming from the characteristics of the light itself which makes deflecting the beam to give the desired scanning mechanically difficult. There is therefore not only the troublesome operation of having to axially move the sample stage as the irradiation position changes, but there is also a problem that the response speed is slow. Beam focusing and beam deflection scanning are relatively straightforward for electron beams and ion beams that employ magnetic means and can therefore be said to be suited to manufacture of this type of ultra-fine three-dimensional structure. However, when a focused electron beam is used, irradiated electrons pass through the material target on which it is wished to deposit the irradiated electrons due to the characteristics of electrons such as particle mass and particle diameter, resulting in a problem where it is difficult to perform deposition at the desired locations which accompanies the phenomena of depositing at locations where deposition is not desired. Taking the above collectively, methods employing a focused ion beam are most appropriate in the construction of ultra-fine three-dimensional structures. Researchers are therefore currently performing various trials with respect to research into the use of focused ion beams.
A description is given using FIG. 4 of deposition using a focused ion beam device. Numeral 1 indicates an ion source. Ions are extracted by applying a voltage to electrodes taken from the ion source 1 and these ions are brought into a beamshape by an ion optical system 3, are deflected by a deflection operation of a deflector, and are made to irradiate desired locations of a surface of a sample 7 mounted on a sample stage 4. Source gas is blown from a gas gun 6 in the direction of the vicinity of the surface of the sample to be subjected to deposition. In doing so, an attractive layer of blown source gas can be formed at the surface of the region of the sample 7 so that when a focused ion beam 2 is irradiated, ions and the source gas react with each other so that a certain product material, i.e., a volatile product material, is deposited on the surface of the sample. When the focused ion beam 2 is made to scan a prescribed region of the sample 7 by the deflector, deposited matter forms a thin film at this region. Deposition employing focused ion beam devices is used in the forming of protective films for providing protection with regards to damage to the surroundings when processing semiconductor devices, etc. using sputtering etching and gas-assisted etching employing focused ion beams and in the correction of white defects (void defects) in semiconductor devices and photomasks, etc.
Researchers are developing technology to cultivate materials in a horizontal direction in research processes for implementing bridging of void defects in the field for correcting white defects of the aforementioned semiconductor devices and photomasks, etc. This technology has been disclosed previously in Japanese Patent Application No. 2000-333368 titled “Beam-Shaped Film Pattern Forming Methods”. With this technology, deposition is executed gradually with respect to a channel-shaped defect of the element at a strip-shaped irradiation region from an end of the channel so that a deposition layer is grown in a central direction while moving the center of an opening of the irradiation region. This phenomena then forms an inclined surface at the tip side of the deposition layer D as shown in FIG. 3. Formation of the sloping surface is performed by sequentially advancing attachment from the ends, because at the time of initial irradiation there is no foundation to become attached to at the tip side of the irradiation region. However, if a temporary foundation is possible, it becomes possible to form a deposition layer D on this base and if the time of irradiation to the same region is made longer, the deposition layer D does not simply become thicker, as shown by the dashed line b in FIG. 3A, but the sloping surface disappears and becomes instead a flat deposition surface. In that way, an edge of the deposition layer D on a growth tip side rises up, and if the irradiation region is subsequently shifted and a deposition layer formed, the next deposition layer grows as a step shape upwards and in the tip direction, as shown in FIG. 3C. In the invention of the previous application, when the tip side of the deposition layer D is being formed in a ledge shape, the irradiation region is shifted to the tip side so as to overlap the sloping surface portion, and deposition is performed again. The deposition layer D is also formed having a sloping surface the second time, as shown by the dashed line a in FIG. 3A. At the point in time when this state is reached, the irradiation region is again shifted to the tip side, and the deposition layer D is sequentially grown on the tip side. Film formation using this method does not produce a stepped shape for the deposition layer of each strip, as shown in FIG. 3B, and it is possible to form a fixed length cantilever beam shaped body positioned at the lower surface. It is also possible to grow directly alongside with a thin film thickness of ten times or more and it has been conformed that this thickness can be formed in a flat and uniform manner.
It is therefore the object of the present invention to provide technology for forming ultra-fine three-dimensional structures using CVD techniques where a source gas is blown onto a sample surface which is then irradiated with a focused ion beam in a straightforward and rapid manner without the necessity of troublesome operations.
Technology is also provided for eliminating ion elements remaining within the sample irradiated with an ion beam during this processing.